Uncovering mechanistic underpinnings of regenerative farming systems on soil organic carbon.

Abstract:

Regenerative farming practices such as no-till, diversified cropping rotations, reduced synthetic input, cover crops, and livestock integration systems have the potential to address worsening trends in soil degradation and climate by enhancing soil organic carbon (SOC) and reducing GHG emissions, but they are rarely considered together on a system level. Adopting a systems-approach that addresses multiple regenerative practices can provide additive or even synergistic effects on key processes driving SOC accrual and increase the overall capacity for agricultural soils to sequester carbon. SOC is very complex and requires separation into multiple components with contrasting properties and behavior in order to study and predict its dynamics. Separating SOC into particulate (POC) and mineral-associated (MAOC) forms, two SOC components that are fundamentally different in terms of their formation, persistence, and functioning, is now recognized as the leading strategy to understand and predict broad-scale SOC dynamics to provide recommendations to managers and policymakers. We will quantify POC and MAOC stocks in soils collected from 24 farms (96 fields) enrolled in the General Mills regenerative agriculture initiative in Kansas. Combining SOC pools data with management, soil health, and biodiversity data we will advance our understanding of the mechanisms promoting SOC storage, and quantitatively assess the ability of a range of regenerative agro-ecological approaches to stimulate long-term SOC sequestration, as well as maintain soil health. Results will be incorporated into a new generation biogeochemical model (MEMS) that can be used in decision support tools to scale up effects of management and provide an analytically tractable framework that can be used to test specific mechanistic hypotheses about C and N cycling in agroecosystems. Findings from this work will have broad impacts through integration with the numerous organizations coalescing around the regenerative agricultural initiative of which this project is part. We will present the overall conceptual framework, project design and initial findings.